1. Field of the Invention
This invention relates to refrigerants, refrigeration oils and refrigerant-refrigeration oils colored with substantially hydrophobic polyoxypropyleneamine substituted anthraquinone dyes. Such substantially hydrophobic polyoxypropyleneamine substituted anthraquinone dyes can readily be incorporated in vapor compression heat transfer systems, such as refrigeration systems employing fluorocarbon refrigerants and refrigeration oils, so that escaping refrigerant and/or oil containing dissolved dye can be easily visible thereby facilitating recognition and location of leaks in the system. Once such leaks have been located they can be readily repaired.
2. Description of Prior Art
The location of leaks in vapor compression heat transfer systems, such as refrigeration systems employing fluorocarbon refrigerants and refrigeration oils, has long been recognized as a difficult problem in the repair of such systems. Various dyes have been employed to indicate the presence and location of leaks in vapor compression heat transfer systems. However, such prior art dyes have generally lacked certain desired properties. For example, many of the dyes heretofore employed have possessed inadequate solubility in refrigerants and/or refrigeration oils, are often too unstable for use at the temperatures encountered in modern refrigeration systems, or severely stain certain finishes, such as acrylic finishes used on automobiles, thus making it impractical to use refrigerants containing such dyes.
It has now been discovered that by incorporating substantially hydrophobic polyoxypropyleneamine substituted anthraquinone dyes into fluorocarbon refrigerants, refrigeration oils and mixtures thereof, leaks in a vapor compression heat transfer system can readily be detected. Further, such substantially hydrophobic polyoxypropyleneamine substituted anthaquinone dyes are stable at temperatures normally encountered in refrigeration systems in the presence of fluorinated refrigeration oils and materials of construction; do not interfere with the normal operation of such a heat transfer system; and, are easily removed from materials, such as clothing, automobile finishes and refrigeration cabinets by the use of dry cleaning solvents.